THE RATE OF GROWTH 129 



milligram, we could, according to the laws of the United 

 States, send 50,000 such germs by letter postage for 

 two cents. It would take 50,000 germs to make the 

 weight of one letter. That perhaps will give you 

 some impression of the extreme minuteness of the 

 primitive germ. In the human species at the end of 

 even a single month it is no longer merely a germ, 

 but a young human being, very immature, of course, 

 in its development, but already very much larger. I 

 doubt even after all that I have said this evening 

 about the startling figures of growth for the earlier 

 stages I doubt if you are prepared for the fact that 

 the growth of the germ up to the time of birth repre- 

 sents an increase of over five million per cent. How 

 much over five million per cent, we cannot calculate 

 accurately, because we do not know accurately the 

 weight of the original germ, but an increase of five 

 million per cent, is not above the true value. 1 Con- 

 trast that with anything which occurs in the 'later 

 periods. What a vast change has happened ! What 

 an immense loss has taken place ! The rate of this 

 loss is evidently diminishing. The loss occurs with 

 great rapidity in the young less rapidly the older 

 we become. 



Professor Richard Hertwig of Munich 2 has reached 

 a similar result by a different method of calculation. 

 He estimates the volume of the human fertilised 



1 Assuming the germ to weigh 0.0006 gramme, and the child at birth 3200 

 grammes, the percentage increment would be 5,400,000. 



2 R. Hertwig, " Ueber die Ursache des Todes," reprinted from Allgemeine 

 Zeitung, Dec. 12, 13, 1906 (Beilage). 



